目的研究髓内骨样骨瘤影像特 点，探讨磁共振在评估冷循环射频消融治 疗效果的应用价值。方法 3例进行冷循环 射频消融术髓内骨样骨瘤，48例行非冷 循环射频消融术的皮质和骨膜下骨样骨瘤 患者，术后观察比较两组影像学变化。结 果 髓内骨样骨瘤X线、CT瘤巢周围软组织 及骨髓肿胀明显，边界不清晰，瘤巢不 典型，部分无周围硬化缘。MRI可查到瘤 巢，髓内呈软组织信号改变，可表现为假 象侵袭性表现。术后所有患者疼痛缓解和 临床症状改善。骨样骨瘤患者中，治疗后 24月随访后，无复发现象。28例骨皮质和 骨膜下型需补加非冷循环射频消融术。3 例髓内骨样骨瘤术后完全治愈。结论 CT 引导的RFTA 将成为儿童第一线治疗方 法，因创伤性低，并发症率少。应用冷态 模型，骨样骨瘤局部治疗是非常有效的。 治疗成功指标是疼痛消失和MR图像骨髓信 号恢复正常。

Objective To study the particular imaging features of intramedullary osteoid osteoma and evaluate success rate of cold mode radio-frequency thermal ablation (RFTA) as the treatment of it. Methods Three patients had tibial intramedullary osteoid osteoma who underwent RFTA and forty-eight patients with cortical and subperiosteal lesions were treated by the non-cooled mode, finally compared the difference between the two groups. Results The swelling of marrow and the soft tissue around the nest, no Clear boundary, the nest is not typical, no hardening around the rim with intramedullary osteoid osteoma. The intramedullary soft tissue changes may show as a misleadingly aggressive appearance in MRI. Treated by the RFTA, all patients were pain-free and in good recovery. In the intramedullary osteoid osteoma group, no recurrences were observed during the 24-month follow-up period, but 28 patients who got cortical osteoid osteoma required a supplementary RF treatment to completely heal the lesion. Three patients had complete healing by the RFTA. Conclusion CT-guided RFTA should be the first treatment for intramedullary osteoid osteomas because of the high success rate and its reduced invasion. With cold-mode RFTA. The outcome is promising. The success indicators for treatment are the disappearance of pain and the absence of lesion in the ablation area detected by MRI.